It was a warm summer night when Dexter Johnson killed Maria Aparece and Huy Ngo.

Along with four friends, the brain-damaged, schizophrenic 18-year-old had carjacked the young couple hours earlier, driving them around town to get money before eventually leading them out into the woods and shooting them both in the head - just one of the many brutal crimes prosecutors say Johnson pulled off during his monthlong spree of violence.

That was all 12 years ago. On Thursday, on a cool winter morning - over Johnson's angry protestations of his innocence - the now-30-year-old got a date with death.

With one appeal still pending in the courts, Judge Denise Collins signed off on a May 2 execution, while the victims' families - who'd filled the benches in the 208th District Court - sobbed and Johnson's family looked to the heavens.

"You changed all of our lives for the worse," said Jose Olivares, whose father Jose was killed in Johnson's string of violence. "I know they say you're supposed to forgive, but I can't forgive till you're dead."

Ngo's sister wept as she addressed the court, while one of Aparece's family members raised his voice, almost shouting as he promised no pity.

Afterward, Johnson - mumbling over the sobs behind him - apologized to the families, even while denying his own guilt.

"I do understand their hate, I do understand," he said. "But I never killed nobody."

The emotionally-charged court appearance drew prosecutors from earlier in the case, including attorney Brian Wice who served as an appointed pro tem earlier in the appeals process.

"This was my first experience as a special prosecutor," he said. "I'd handled over a dozen death penalty appeals and writs and until today I never really had a sense of what the families of the victims are going through and how they may never obtain closure for a loss that can only be described as unspeakable."

In the years since he was sent to death row, Johnson has fought his sentence with appeals based on bad lawyering, racial bias, intellectual disability and his long history of schizophrenia and psychotic breaks.

"Mr. Johnson has significant brain damage that is at the root of this tragedy, and that same damage has made him unable to help his defense throughout this process," defense attorney Pat McCann said last year. "He has an actual hole in his brain where functional brain matter ought to exist."

Thursday's court setting was significantly calmer than the trial that put him on death row more than 10 years ago. Then, two of his relatives collapsed in the hallway, while the mother of his child lay on the floor moaning and breathless after hearing the verdict. At one point he'd refused to come to his own court dates. Later, he hurled a chair across the courtroom.

"My son is no murderer," Renee Johnson told the Chronicle at the time. "He didn't have it in his blood."

But it took a Harris County jury only two hours to find him guilty of the carjacking, rape, robbery and murder. The night of the June 2006 crimes, Johnson and four accomplices came across the young couple sitting in Aparece's Toyota, where they were chatting outside Ngo's home. Johnson and two others threatened them with a pistol and a shotgun, according to testimony at trial.

Then, three of the attackers drove the young couple around Houston in Aparece's car, stealing her cash and credit cards and trying to get money from her bank accounts. Behind them, two other accomplices followed in their own car.

Eventually, the violent crew pulled over and, according to trial testimony, Johnson raped Aparece in the backseat. Her boyfriend was forced to listen to it all on his knees as the other attackers taunted him.

Then, Johnson shot Ngo in the head before slaughtering Aparece. At trial, Johnson's defense team argued that it was someone else who walked the couple into the woods and fired the fatal shot.

It took investigators five days to figure out what happened.

After a quick guilty verdict, jurors heard testimony about the monthlong crime spree before and after the double slaying. That May, prosecutors said, Johnson killed a 60-year-old man washing his barbecue pit at a local car wash.

A few weeks later - the day before the slayings that put him on death row - Johnson and a partner in crime robbed two men standing at a pay phone, killing one after he offered them only a roll of quarters, prosecutors said.

In the days that followed, Johnson and his confederates pulled off a string of other robberies,. Then, according to trial testimony, he was potentially involved in the murder of a man inside his car on Annunciation Street.

In his appeals since then, Johnson's attorney has focused on arguments alleging that his client lacked the brain functioning to be held to the same standard as adults. Instead, he drew parallels to past court decisions that ban executing juveniles and the intellectually disabled, saying similar reasoning should be applied to Johnson's brain damage.

"If you have an actual hole in your brain that you could basically run water through at that point you have to recognize that this is a person who's not fully responsible for what they're doing," McCann said earlier this year.

The Lone Star State has executed 12 men this year, and another is scheduled to die next week. Including Johnson, there are five executions scheduled so far for 2019.